I agree with printing Fly Tying 101 from here but the book I would recommend is A Fly Tyer's Guide To Fishing Flies. It starts off by explaining the tools, materials, and hooks. Then it explains each step used in tying from fixing the hook to the vice, through thread tying on and whip finishing, tails, wings, hackle, dubbing, and wings. Then it proceeds with simple flies using the steps learned with pictures for each step. There is a section on some of the knots used.
The last 5 chapters are recipes for flies, 30 dry, 30 wet, 18 salmon and sea trout flies, 18 lures, 21 nymphs and buzzers. The recipes are for the most commonly used flies and give a good head start on creating custom patterns.